Means for the prevention of vapor lock in the fuel feed of internal combustion engines



g- 26, 1941. B. M|NNERNEY 2,253,717

MEANS FOR THE PREVENTION OF VAPOR LOCK IN THE FUEL FEED OF INTERNALCOMBUSTION ENGINES Filed June 4, 1940 .8? x as /n van for.-

, ward by lever Patented Aug. 26, 1941 LOCK IN MEANS-FOB. m PREVENTIONor varon THE FUEL FEED OF INTERNAL COMBUSTION ENGINES BenjaminMclnnerney, Omaha, Nebr.

Application June 8 Claims.

4, 1940, Serial No. 338,706

My invention relates to improved means for preventing the accumulationof vapor in the pump and tubes which supply and conduct fuel from thefuel tank to the carbureter of an internal combustion engine. otherobjects which may be included in the .construction of the apparatus willalso be disclosed in this application.

It is common practice to use an engine driven pump for the purpose offorcing fuel to the carbureter of an automobile engine. The pump usuallyhas a diaphragm which is flexed in one direction by a moving part ofthe. engine to draw fuel from the supply tank to fill the suction pipeand pump chamber, and inthe opposite direction by a spring which exertsa resilient pressure on the fuel, tending to force it into thecarbureter as it is consumed.

When the fuel spaces are full of fuel, and while the temperature of thefuel remains below its vaporizing point the pump may operatesatisfactorily but during hot weather, and especially in high altitudesand while the car is climbin heavy grades, vapor is sometimes generatedin excess of the displacement capacity of the pump; this results'in thefuel spaces becoming partially filled with vapor which displaces theliquid fuel'and if not arrested it finally forms the commonly knownvapor lock; causing the engine to lose power and sometimes stop becauseof insufficient fuel.

The principal object of my invention is to remedy this condition and Iattain this object by the use of the apparatus illustrated in theaccompanying drawing, in which:

Figure 1 includes a verticalsection of the fuel outlet portion of atypical pump, which is designated by the letter A, a vertical sectionshowing one form of my invention in its preferred position, designatedB, and a partial elevation of the fuel inlet portion of a typicalcarburetor, designated C. Figure 2 is an end elevation of my apparatus Bviewed 3 is a vertical section of a simpler form of the apparatus whichis adapted to installation in places where there may not be room for theform shown in Figures 1 and 2. Similar numerals refer to similar partsthroughout the drawing.

Pump A, Figure 1, is provided with diaphragm l and stud link 2; thisassembly is moved down- 3 which is actuated by a moving part of theengine; usually an eccentric on the cam shaft. The downward movement of'the diaphragm serves to draw fuel into the pump chamber, whilecompression spring 4 urges the Details relating tomon use.

- through which the condense an unusual surge of vapor.

from line 25-26. Figure diaphragm upward between strokes, thus providinga resilient pressure on the fuel, forcing it through outlet check 5 andtube 6, which is connected to apparatus B at 1. The parts thus fardescribed are typical of those now in com- My apparatus B, Figure l, isprovided with inlet opening I, upwardly extending tube 8, condensingchamber 9, downward extending passage l0, and fuel bowl II which has forits principal purpose to provide means for submerging the lowerendoftube I4 so long as any fuel remains in the condensing chamber.

Fuel bowl II is also adapted to act as a sediment trap and screenchamber by being provided with'plug l2, which may be removed to flushout any accumulated sediment, and screen l3 fuel passes to the lower endof tube' H, which leads upward to valve seat l5.

Valve seat l5 may be a forced fit in casing B or it may be threaded intoplace. Disk valve I6 is seated on the upper held seated by spring l1,thereby preventing fuel flow-back from the carbureter.

Tube Hi, the upper end of which is closed by cap I9 serves to store asmall amount of fuel, which may be 'drawn into the carbureter by thesuction therefrom during the time required to It may also serve to primethe carbureter in case the fuel spaces are empty, as .in case the carhas been unused for sometime orafter repairs which required draining thecarbureter; thus avoiding the drain on the from rotating the engine thepump to fill the fuel spaces.

Heat deflector 20 is attached to the base of apparatus B byscrews 2l-22. An extension 23 is adapted'to be placed at either side in positionto deflect the direct heat of the engine ;from condensing chamber 9. Inmany installations a shield on one side serves but the V type engineusually has the carbureter directly above and between the heatedcylinders, to install two extensions 23.

"Condensing chamber 9 is preferably made of thin copper tubing, closedat the top and flattened as shown in order to spread the contents thinlyagainst a relatively large radiating area. I prefer to further increasethe'radiating area by means of the thin metalflns.

I shall now refer to Figure 3-which is adapted to installations in whichthe room above the carbureter inlet is limited, and which is shownsomewhat simpler than the form shown in Figure face of seat l5 and isbattery which would result long enough to enable making it desirable 1,in that it does not include the sediment trap and screen, although it isobvious that these elements may be added if desired. The form shown inFigure 3 includes the main operating features heretofore described. Thefuel enters at 1' and is forced upward through tube 8' into condensingchamber. 9', then downward into fuel bowl ll, upward through submergedlower end of tube 14 valve seat valve l6. into carbureter C, whilechamber I. is adapted to store reserve fuel as heretofore describedwhile referring to Figure 1.

I shall now describe the operation of my invention. While-the engine isrunning a stream of air is being forced into the engine space by theradiator fan, this air stream passes between fins 2424' and in contactwith the outside surfaces of chamber 99' as shown by the arrowed linesa:a:, tending to lower the temperature chamber 99'. v a r In case vaporforms in the fuel the vapor bubbles follow the natural law of vapor inliquid and collect in the upper portion of the fuel passage. As theypass into chamber 9+9 they are directed upward toward the top of thechamber by tube 8-8 and are there condensed fuel which occupies muchless space, thus a vacuum is created, which, in case the carbureter fuelvalve is closed, assists in drawing fuel through the tubes and pump, andthus by filling the fuel spaces with liquid assists in restoring thepump to normal operation.

In case the fuel has lowered in the carbureter, allowing the float todrop and open the carbureter fuel valve, and if no means are provided toprevent fuel flow-back from the carbureter and storage chamber |8--l8'the vacuum resulting from condensation of vapor would tend to draw fuelfrom the carbureter supply as the hydrostatic head is less than from thepump, I therefore provide check lG-IB' to prevent flowback, thus in casethe carbureter fuel valve is open check valve l6|6' permits the suctionresulting from vapor condensation to be exerted only to draw vapor andfuel through the pump and supply tubes, thus displacing the accumulatedvapor and providing space for liquid fiiel.

A condition may result from extreme heat, high altitude, or whileclimbing an excessive grade which lowers the fuel tank, thereby imposingadded work on the pump and lowering the vaporizing point of the fuelbecause of the increased ,vacuum required, during which period anexcessive surge of vapor may be formed. Tube l8-l8' is adapted to storea small quantity of fuel iii order to provide against loss of powerduring the interval required to condense this excessive vapor surge.

It will be noted that the apparatus is adapted to function in accordancewith the natural laws governing th action of vapors in liquids. 'I'hefueP is forced upwards into chamber 9-9 in the form shown in IE andunder check into liquid design is adapted to include, inexpensively, anefficient sediment trap and, screen.

I claim: 7

1. In combination with an internal combustion engine having a fuel pumpand a carbureter, a condensing chamber'in series with the fuel conduitbetween the pump and the carbureter, means for conducting the fuel intosaid chamber,

then downward from the lower portion of the ber to a vfuelreceptacle,from the lower portion of which an upwardly extending passage leads tothe carbureter, and a shield attached to, or forming an integral.adapted to deflect the direct heat of the part of the assembly andengine from the condensing chamber.

3. In combination with an internal combustion engine having a fuel pumpand a carbureter, a condensing chamber in series with the fuel conduitbetween the pump and the carbureter, means to a check valve which forconducting the fuel into said chamber, then downward from the lowerportion of the chamber to a fuel receptacle, from th lower portion ofwhich an upwardly extending passage leads to flow to the carbureter 4.In combination with an internal combustion engine having a fuel pumpanda carbureter, a condensing chamber inseries with the fuel conduitbetween the pump and the carbureter, means for conducting the fuel intosaid chamber, then downward from the lower portion of said chamber to afuel receptacle; from the lower portion of which an upwardly extendingpassage leads to a check valve which is adapted to allow fuel to flow tothe carbureter, and a fuel storage chamber having connection with theconduit between said check valve and the carbureter.

5. In combination with an internal combustion engine having a fuel pumpand a carbureter, a

condensing chamber in series with the conduit between the fuel pump andthe carbureter, means for conducting the fuel into said chamber,

' then downward from the lower portion of the chamber to a fuelreceptacle, from the lower portion of which an upwardly extendingpassage leads to a check valve which is adapted to allow fuel to flow tothe carbureter, a fuel storage chamber having connection with theconduit bethe upper portion of which any vapor bubbles while saidstorage chamber is adapted to provide fuel during the time required torestore the pump to normal operation; and if desired the tween saidcheck valve and the carbureter and a normallyclosed opening in the upperportion of said storage chamber adapted to be opened for the purpose ofpriming the carbureter.

6. In combination with an internal combustion engine having a;.fuel pumpand a carbureter, a condensing chamber in series with the fuel conduitbetween the pump and the carbureter, means for directing the fuelupwardly into the condensing chamber, then downwardly into a fuelreceptacle which is provided with means for draining out sediment, thenupwardly through an outlet leading from the lower portion of saidreceptacle to the carbureter.

7. In combination with an internal combustion engine having a fuelpumpand a carbureter, a condensing chamber in series with the fuelconduit between the pump and the carbureter.

is adapted toallow fuel ing chamberrthen downwardly into a fuelreceptacle which is provided with means for draining, then upwardlythrough a screen and into an outlet leading from the lower portion ofsaid receptacle to a check valve which is adapted to allow fuel to flowto the carbureter, a fuel storage chamber having'connection with theconduit between the check valve and the carbureter, and a shield adaptedto deflect the direct heat of the 10 engine from the condensing chamber.

BENJAMIN MCINNERNEY.

